The Foundation's year-round Department of Science and Stewardship works closely with seasonal field assistants and volunteers, as well as outside collaborators on many different projects related to better understanding, managing, and protecting the rare and unique resources found on our properties. Below is a summary of the current research projects that we are working on.
If you would like to receive more information about any of the research projects described below, please contact Dr. Jennifer Karberg, Research Supervisor for the Science and Stewardship Department.
Property Management Plan Development
In 2004, following a Board Initiative, the Foundation's Science and Stewardship Department began developing Property Conservation Management Plans. The major goals of these plans are to identify the management needs and conservation concerns of natural communities and species on each Foundation property and inventory species and habitats of special concern. These plans will guide future research and management. Property Management and Conservation Plans have been completed for the Foundation's Head of the Plains, Eel Point, Squam Farm and Sanford Farm properties. Additional plans are currently being developed.
Head of the Plains Prescribed Fire Effects on Vegetation Community Composition and Rare Species Dynamics
The Foundation's Head of the Plains property represents one of the larger contiguous areas of sandplain grassland and coastal heathland plant communities remaining on Nantucket. These vegetation communities, besides being globally rare, also host a suite of plant and animal species of special concern in New England. For this reason, developing effective management strategies for this property is a high research priority.
Sandplain communities evolved in response to frequent disturbances, perpetuated on Nantucket primarily through fire and sheep grazing, and in some part through wind and salt spray. In order to prevent encroachment by woody species, disturbance of some form - prescribed fire, mowing, grazing, etc, is necessary. In 2005, the Science and Stewardship Department embarked upon a comprehensive research project to examine the effects of seasonal prescribed fire at the Head of the Plains. Research-oriented prescribed burns were initiated in September, 2005. The research design involves conducting three burns (10-15 acres per burn) during the late growing season (September), fall dormant season (November) and spring dormant season (March). During each burn, we place thermocouples (devices that measure temperature at one second intervals) at 30 permanent vegetation monitoring plots, where we have collected detailed plant species data prior to the burns. Seasonal monitoring of the vegetation response to prescribed fire characteristics (flame temperature and duration, seasonality of burns, drought index, and other environmental variables) will help us make educated decisions about when and under what conditions to employ this management tool on Nantucket.
In addition to studying plant community responses to prescribed fire, we also monitor rare plant populations found at Head of the Plains, including Nantucket shadbush (Amelanchier nantucketensis), bushy rockrose (Helianthemum dumosum), sandplain blue-eyed grass (Sisyrinchium fuscatum), New England blazing star (Liatris scariosa var. novae-angliae), papillose nut sedge (Scleria pauciflora var. caroliniana), and sandplain flax (Linum intercursum). We annual monitor these populations within established rare species plots in order to document population changes and species demographics over time and in response to prescribed fire.
Comprehensive monitoring will help us fine-tune prescribed fire as a management tool to maintain and expand critical sandplain grassland and coastal heathland communities through documentation of short and long term effects of prescribed fire on vegetation community composition and rare species dynamics.
Restoration of the Medouie Creek Wetland Complex
The Medouie Creek wetland complex is located on the northern shore of Polpis Harbor. It is composed of natural salt marsh and an historic salt marsh that, due to diking in the early 20th century, was converted to a hydrologically restricted freshwater marsh. The impounded and diked portion of Medouie Creek, after many decades with minimal salt water inputs or tidal action, now contains freshwater plant and animal communities. The site is also in the process of being invaded by common reed (Phragmites australis), a highly invasive wetland plant.
In December 2008, the Foundation implemented a salt marsh restoration plan involving the placement of a culvert through the dike road, allowing the flow of salt water into the previously restricted freshwater marsh. The goals of this restoration project include reestablishing the ecological conditions that favor salt marsh vegetation, soils and hydrology and, hopefully, reducing populations of common reed, which research indicates is sensitive to increased salinity.
This research project represents one of the most intensely-monitored salt marsh restoration projects in New England. Vegetation community monitoring initiated pre-restoration will be repeated every two years to document post-management plant community shifts in the previously restricted freshwater marsh. In addition, during the growing season, soil pore water salinity measurements are taken twice monthly to measure increases in salinity in the rooting zone of plants. Water level data loggers placed in strategic locations throughout the marsh measure changes to water flow and increased tidal action in the previously restricted marsh.
Over the next few years, we expect to see a steady increase in salinity and tidal action in the previously restricted marsh as well as a reduction in freshwater plant species. Conversion to a full or even partial salt marsh plant community may take many years. Based on the impact of salinity over the next few years on the population size and viability of common reed, we will reassess management options for controlling and possibly eradicating this invasive species.
Ecology of Spotted Turtles
The spotted turtle (Clemmys guttata) is a small, semi-aquatic , freshwater species of eastern North America. It is distributed from southern Ontario to Maine, south along the Atlantic Coastal Plain to northern Florida, and west to northern Indiana. Throughout much of its range, this species is considered threatened, endangered, or vulnerable, primarily due to degradation and fragmentation of wetlands, mortality from crossing roads and collection for the pet trade. In 2006, the spotted turtle was removed from the list of species protected by the Massachusetts Endangered Species Act. However, it is still illegal to collect, sell or possess a spotted turtle. Despite the de-listing of this species, the Nantucket Conservation Foundation believes continued monitoring of spotted turtles on Nantucket is warranted because island populations often face ecological challenges such as physical and genetic isolation from mainland populations, limiting migration and gene flow between populations. Results from research on Nantucket's populations of the spotted turtle could potentially be applied to conservation and management of mainland populations that have become isolated due to habitat fragmentation.
In 2008, the Science and Stewardship Department concluded a study on spotted turtles at our Squam Farm property. We used a mark/recapture framework and radio-telemetry to document population size, habitat use, and seasonal home range size. These data are providing us with the tools to implement management on this property that minimizes impacts to spotted turtles and their habitat.
Furthermore, we are currently monitoring spotted turtle populations at the Medouie Creek wetland complex in order to document changes to habitat use and movement patterns in response to increased salinity in the marsh. While these freshwater turtles are occasionally found in brackish water, we expect to see a shift in home range and habitat use as tidal action and salinity increase throughout the marsh.
Understanding movement patterns and wetland versus upland habitat use on these properties will help us make more informed management decisions aimed at assuring the continued health of spotted turtle populations on Nantucket.
Effectiveness of Management Techniques on the Nantucket Shadbush
Nantucket shadbush (Amelanchier nantucketensis) is a low growing, clonal shrub that is regionally rare but relatively abundant within Nantucket's sandplain grassland and coastal heathland communities. It is currently listed as a "Species of Special Concern" by the Natural Heritage and Endangered Species Program of the Massachusetts Division of Fisheries and Wildlife (MassNH&ESP). Nantucket shadbush grows in open sunny areas on dry, sandy soils with little competition from larger woody plants. It appears to respond positively to periodic disturbance such as fire and brush cutting which reduces competition from other woody plant species. Funding provided by Mass NH&ESP in 2007 helped facilitate research to examine the effects of prescribed fire and brushcutting on two Foundation properties.
At the Foundation's Head of the Plains properties, patches of Nantucket shadbush are being managed with prescribed fire. A suite of plant physiological and population characteristics of Nantucket shadbush are being measured in established prescribed fire management units and in unburned control units. We are comparing the managed population of Nantucket shadbush to pre-treatment data and to untreated control data in order to examine the influence of burning vs. no management. At the Foundation's Trott's Hills property, we are conducting a similar study to document the response of Nantucket shadbush to brushcutting. Data from these studies will aid the Foundation in planning effective management of this rare species in the future.
Effectiveness of Disk Harrowing as a Grassland Restoration Tool
The Nantucket Conservation Foundation is an active participant in the Partnership for Harrier Habitat Preservation (PHHP) which was initiated in 1996 to compensate for rare species habitat altered by the development of a golf course on Nantucket. The goal of the PHHP is to restore sandplain grassland and coastal heathland vegetation communities and associated rare species habitat within the shrub-dominated communities of Nantucket's Middle and Eastern Moors region. Consequently, approximately 500 acres in the Middle and Eastern Moors are currently being managed by annual mowing to limit the encroachment of woody vegetation, specifically scrub oak (Quercus ilicifolia), and to encourage the establishment of forb and graminoid species.
Mowing in the Middle and Eastern Moors reduces the height of woody species but does not significantly reduce woody cover. Furthermore, mowing produces only minimal increases in graminoid (grass-like) plants and fails to promote growth of herbaceous plants. Consequently, the Foundation initiated a research project exploring the use of disk harrowing (a form of tilling that breaks up topsoil and root masses) as a management technique to reduce woody cover and increase graminoid and herbaceous species. We conducted experimental harrowing at two locations in the Middle and Eastern Moors in 2007 to determine the ability of this management technique to decrease woody species cover and promote an increase in graminoid and herbaceous species cover, and have been annually monitoring the response.
Preliminary analysis of the Middle and Eastern Moors harrow research suggests a substantial decline in woody species cover by as much as 50% compared to pretreatment cover, at least in the short term. However, there has been no significant increase in graminoid or herbaceous cover. Another research project at these two sites examining the soil seed bank indicates that grassland seeds may not be present within the soils of these shrub-dominated sites. After analyzing data collected in 2009, the Foundation will determine the next direction for this research project.
Exploring Seed Bank Composition to Improve Habitat Management Techniques
As described above, a majority of the research projects of the Foundation's Science and Stewardship Department explore the use of management tools (mowing, harrowing, grazing, and prescribed fire) to restore existing scrub oak shrubland to grassland and heathland plant communities. Some major questions exist - do scrub oak shrubland communities have sufficient stored seed banks of coastal sandplain species necessary for successful grassland restoration? When we manage existing scrub oak shrublands with harrowing, mowing or burning, will seed addition be necessary to facilitate conversion to a grassland or heathland dominated community?
In an attempt to answer these questions, the Foundation initiated a soil seed bank study. In 2007, we collected soil cores from representative grassland, heathland, and shrubland communities located in various conservation areas on the island owned by the Nantucket Conservation Foundation, Nantucket Islands Land Bank, and Massachusetts Audubon Society. Collected soil cores were over-wintered and germinated in the Foundation's greenhouse. Seedling germination was recorded and individual plants were identified to the highest taxonomic level possible.
Preliminary results indicate that shrubland seed banks contain a dramatically smaller component of germinable grassland species compared to seed banks in areas currently dominated by sandplain grassland or heathland communities. Our findings suggest that the addition of native, locally-collected seed may greatly enhance management efforts such as harrowing aimed at converting shrubland to grassland habitats. Based on these results, we have started collecting seed of key grassland species such as little bluestem grass (Schizachyrium scoparium) and a variety of native wildflowers for use in future management utilizing seed addition.
Wetland Habitat and Rare Species Management at the Sconset Dump
The ‘Sconset Dump is a unique, anthropogenically-created acidic fen wetland that hosts a large number of rare plants. These rare species are all sun-loving species and thrive in an open habitat with little competition from larger woody shrubs and trees. In the winter of 2008, Foundation staff, in consultation with the Massachusetts Natural Heritage & Endangered Species Program and permitting from the Nantucket Conservation Commission, initiated management to remove taller shrubs encroaching along the margin of the wetland to increase habitat for the unique plant community at this site.
Post-management, the Foundation is monitoring populations of rare plant species, particularly Torrey's beak sedge (Rhynchospora torreyana), tall nut-sedge (Scleria triglomerata), subulate bladderwort (Utricularia subulata) , Mattamuskeet panic-grass (Dichanthelium dichotomum), beaked pinweed (Lechea pulchella) and the thread-leaved sundew (Drosera filiformis) . In addition to monitoring population dynamics of these rare plants, the Foundation is also monitoring the size of the open habitat within the wetland and conducting photo monitoring to determine if/when management will need to be reapplied at this site to prevent the shrub encroachment.
Many of our projects are multi-year research projects. As projects wrap up and final reports are written, they will be made available on this website. Please see our Reports page for current research project reports.